Repair complexity
Replacing a fixture in place is a different job than opening a wall, rerouting a branch line, or chasing a leak that only shows up sometimes.
Access and restoration
Reaching pipe behind plaster, old brick, stone foundations, or a finished basement adds protection and patch-up work on top of the plumbing itself.
System choices
Tank size, material compatibility, valve grade, drain condition, permit needs, and after-hours scheduling all push the estimate one way or another.
Planning note
Ask for a scope in writing, tied to your actual house. Any number given before someone’s looked is a guess, not an offer.